Process of painting metal surfaces.



No. 663,28I. Patented Dec. 4, I900. R. KOPP.

PROCESS OF PAINTING METAL SURFACES.

(Application filed Mar. 21, 1900.1

(No Model.)

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a Noun/1 Q ViM/wooea THE NORRIS PETERS co, FNOTO-UTHQ, WASHINGTON. n. c.

Unrrs Futon.

ROBERT KOPP, OE \VASI-IINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO THE KOPP ANTI-CORROSIVE AND ANTI-BARNACLE PAINT COMPANY, OF

SAME PLACE.

PROCESS OF PAINTING METAL SURFACES.

SPECIFICATION forming part of Letters Patent No. 663,281, dated December 4, 1900.

A li ati filed March 21, 1900. Serial No. 9,567. (No specimens.)

To all whom it may concern:

Be it known that I, ROBERT KOPP, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Protecting Metallic Structures, of which the following is a specification.

My invention has for its object to effectually protect metallic structures, and to this end to prevent the blistering and corrosion which results from the ordinary means employed to apply protective coatings, more especially in structures subjected to the action of salt water; and my invention consists in depositing upon the surface to be coated, after cleansing such surface,a film of coal-oil (crude or refined) and immediately upon this film a suitable anticorrosive coating, and thereafter if the structure is to be subjected to the action of salt water an antibarnacle coating is applied.

In the accompanying drawing, a part A of the side plates of a vessel is illustrated in perspective in a partially-protected condition, a representing the film of coal-oil upon part of the surface, I) the coating of anticorrosive paint applied to part of the surface covered with the film of oil, and c a coating of antibarnacle paint covering part of the surface protected by the coating Z).

In applying the protecting-covering to the structure the surface of the plate is cleaned in any suitable manner. Such structures even after they are cleaned and dry have minute cracks, perforations, joints, 850., at the surface, in which moisture is retained in a way which has rendered its complete removal impossible,except by heating the plate, which in most instances cannot be done practically. The application of a paint to such a surface simply locks the moisture in the interstices, so that in a short time the structure begins to rust below the paint, the latter blisters and peels 0E, and the metal is exposed and soon corrodes. Attempts have been made to prevent such results by applying vegetable oil to the surface of the structure, drying it, and then applying paint, but with only partial success, as all such oils are too thick and viscid to penetrate the minute fissures which tend to retain the moisture.

I have found after many and long-continued experiments that coal oil acts differently from either vegetable or animal oils and produces results which cannot be attained by either. Thus while such oils have alimited protecting effect they have no action in loosening the particles of oxid and exposing the metallic surface, while coal-oil is extremely effective in this respect. Again, such oils will extend over minute cracks and fissures Without penetrating the same, while I have found that in coal-oil there are always portions which. are taken up by capillary action into the most minute fissures and openings, so as to displace any moisture therein, while the body of the oil affords a surface-coating film which effectually covers every part of the metal and which will be retained thereon in effective condition until the anticorrosive paint is applied. When this is done, the oil combines with part of the paint and carries it into the interstices and the paint and oil tend to unite, securing a close adhesion to the surface. By the term coal-oil as used herein I include either crude oil or kerosene. A plate thus coated has proved by numerous tests to be fully and permanently'protected from corrosion until exposed by the actual wearing away of the paint, as the metal will not rust below the paint, and therefore there are no blisters.

Any suitable anticorrosive paint may be employed. One which has proved in practice to be exceedingly effective consists of red lead, French zinc, and Portland cement in about equal proportions, combined with oil and drier, and to this when used for marine purposes is added arsenic or other substances which will have a poisonous effect upon vegetable or animal life. This is used, applying two or more coats, evenif antibarnacle paint is also employed, as it will protect against barnacles after the wearing away of the outer coating. It is necessary that the metallic surface shall be completely and fully covered with coal-oil at the time the paint is applied, and therefore it is desirable that the paint be applied at once after the application of the oil and before the latter has a chance to dry or run off.

When protection against marine life is desired, an antibarnacle paint is applied upon that already used. Any suitable paint of this character may be used; but Ihave found that very satisfactory results may be secured by the following composition: red lead, metallic zinc-dust, verdigris, arsenic, cement, French zinc in equal parts, by weight, with oil, and a drier.

By French zinc I mean the article commercially sold under that name, being an oxid of zinc made in France and having more body than the oxid made in the United States.

ROBERT KOPP.

Witnesses:

H. M. GILLMAN, J r., W. CLARENCE DUVALL. 

